An afternoon of often uncomfortably close attention from Sunderland players ended for Wilshere when a 50th-minute collision with Alfred N'Diaye exacerbated the thigh injury he had sustained in the first half to the point where he could barely walk.

The good news for Arsenal and England fans is that the damage is superficial and the midfielder should be back playing next week but, minor or not, Wilshere's latest wounding raised some important questions. Are referees affording the 21-year-old sufficient protection? And, most pertinently, does a sometimes gung‑ho footballer need to change his game to survive long term?

Wilshere only recently returned after 15 months on the sidelines with ankle and knee trouble but Arsène Wenger will not be asking him to alter a style that, some say, exerts too heavy a toll on his body. "It's Jack's game and he has to take that gamble," said Wenger, who was particularly upset by one unpunished challenge from Titus Bramble. "Jack's game is to take the ball and go at people. Lionel Messi does that as well and he plays without being injured.

"You can only make a career with the strong aspect of your game and that's Jack's strength. You say to him 'play like you play, like who you are and express yourself the way you feel'."

Like Messi, Wilshere must learn to cope with some suffocatingly tight marking and sly kicks. "From very early in the game Jack was handicapped," Wenger said. "I have had a word with him about tight marking but I don't want to talk too much about that as I don't want to transform the player to an attitude of paranoia. I've told him 'just be natural and play your game'. It's down to referees to protect him when it's needed. I think Jack can handle it. I don't go into a paranoia."

Perhaps; although Martin O'Neill suggested his Arsenal counterpart was being a bit, well, paranoid. "There was no foul on Jack Wilshere," said a straight-faced Sunderland manager whose relocation of Stéphane Sessègnon from the hole to the right wing succeeded in discomfiting Nacho Monreal but also emphasised the repeatedly frustrating poverty of Sessègnon's final ball.

Happily for Wenger, Santi Cazorla has few problems finishing what he starts. The Spanish creator not only scored the winner – his low shot beyond the excellent Simon Mignolet a fitting conclusion to an exquisite passing interchange also involving Wilshere and Theo Walcott – but also enabled Arsenal to control much of the first-half tempo.

Later though, a combination of Mignolet's saves, misfiring Gunners and Carl Jenkinson's 62nd-minute sending off for a second bookable offence – a rash tackle on Sessègnon, who had swapped wings with the underwhelming Adam Johnson – allowed Sunderland back into the game. By the end Arsenal were clinging on for a victory vital to sustaining their hopes of a top-four finish.

"We're a massive club and we never want to be out of the Champions League," said Mikel Arteta after a second half spent largely protecting a defence in which Bacary Sagna impressed as an emergency centre-half following Laurent Koscielny's warm-up injury. "Ten years ago it was easier to get into the top four. There are so many more sides out there with equal spending power now. There's been a big improvement in English football; there's no other league in Europe where it's as hard to get into the Champions League."

Arteta identified the next four weeks – featuring an FA Cup tie against Blackburn, a Champions League duel with Bayern Munich and Premier League games against Aston Villa and Tottenham – as pivotal to Arsenal's medium-term future. "This next month is the month, it's crucial," he said. "Everything can look brighter at the end of it or really, really bad."

Lee Cattermole's career seems at a similar crossroads. Back, arguably too soon, from a knee injury, O'Neill's captain was booked for a late, idiotic, third-minute tackle on Aaron Ramsey and was replaced at half-time. Wilshere's game may not require adjustment but if Cattermole is to make the most of his genuine, underrated, ability – while preserving those knees – he needs to start thinking rather than lunging and begin intercepting instead of tackling.